70- Foreign process packages use coalescing screens in the design of oil-water coalescing separators and gas-oil-water three-phase separators
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This post was last edited by luoli519 on 2020-1-4 at 12:00. In domestic petrochemical projects, as well as in oil and gas extraction projects, companies have consistently used process packages provided by certain foreign companies. However, in recent years, as international technical exchanges have become more extensive and in-depth, it has become clear that the screen-type liquid-liquid coalescing separators used in some foreign process packages adopted by domestic enterprises still rely on technologies from the 1980s and 1990s; these separators have low operational efficiency and high maintenance costs. New technologies have not been promptly applied to upgrade and improve these process packages, resulting in a large technological gap between domestic and international standards. It is everyone’s responsibility to work together to discuss the problems that arise in the actual operation of these mesh-type liquid-liquid coalescing separators, as well as possible solutions. Domestic companies should help themselves by upgrading and improving the equipment used in such projects, in order to narrow the gap between domestic and foreign technologies.
For a considerable period of time in the past, domestic enterprises and engineering companies paid little attention to the development of domestic technical projects and process packages, preferring to take shortcuts by purchasing ready-made foreign process packages. Looking back at the experiences and lessons from the past few decades, it becomes clear that certain foreign companies are unlikely to sell their advanced manufacturing techniques and products to others, thereby creating competitors for themselves. To this end, domestic enterprises need to broaden their horizons and make full use of engineering and technical personnel who have accumulated technical experience over many years working on various international technology platforms, in order to gradually carry out self-improvement, enhancement, and innovation in domestic technologies.
This post was last edited by luoli519 on 2019-12-25 at 10:46. Next, let’s take a look at the pictures of the mesh-type liquid-liquid coalescing separators (mesh-type oil-water coalescing separators) that a well-known foreign process package supplier requires to be used in its process packages, as adopted by many domestic petrochemical companies, and then discuss them accordingly:
UOP’s horizontal screen-type liquid-liquid coalescing separator is used for hydrocarbon/water coalescing separation. The screen-type coalescing internals included in the process package must be of Type A screen coalescing internals, with the following parameters: apparent density of the screen of 9 Ib/ft^3, fiber diameter of 0.011 inches, and material made of SS316.
This post was last edited by luoli519 on 2017-1-4 09:20. It’s not that wire mesh types cannot be used for the internal components of hydrocarbon/water coalescing separators. Rather, it discusses that the hydrocarbon-water mesh coalescer separator cannot rely solely on mesh internals as stated in the UOP documents. Everyone, please look:
Many technicians in domestic engineering companies also know that if only screen-type coalescing internals are used to achieve the required separation efficiency, the diameter and length of the separator shell will be very large, resulting in high manufacturing costs for the shell. However, the engineering company either does not want to implement measures to increase the degree of separation of the screen-type coalescing internals due to fear of taking on risks and the effort involved, or it avoids incurring additional costs for its own EPC contract reasons, deciding to address the issue once the installation is completed and put into operation.
Many owners have found during the actual operation of the equipment that the degree of separation between the oil phase and water phase streams at the outlets of the mesh-type liquid-liquid coalescing separator is not satisfactory. The owner reported the situation to the engineering company, which replied that the design was carried out in full accordance with the requirements of the foreign process package, and that any issues should be addressed with the foreign provider of that process package. The emails sent by the owner and the engineering company to the foreign suppliers of the process packages went unanswered, with no response at all.
This post was last edited by luoli519 on 2017-1-3 at 12:29. Here, a gas/oil/water three-phase separator used by a major oil company in offshore deep-water oil and gas projects is presented. Interestingly, the oil/water coalescing separation internals for these two gas/oil/water three-phase separators also employ mesh-type coalescing internals as required by the process package. As shown in the figure below:
By comparing the mesh-type oil-water coalescing internals on floors 3 and 8 of this post, it can be seen that one of the differences is: UOP uses stainless steel SS316 for its mesh material, while Technip uses glass microfibers. From the perspective of surface chemical wettability, the latter is more suitable for oil-water coalescence separation.
The last edit to this post was made by luoli519 on 2023-10-2 at 14:32. The second difference is that the screen-type coalescing and separation internals in the UOP process package do not have additional vaned separation pre-coalescing internals or enhanced sedimentation internals installed before or after them. In the Technip process package, vane separation pre-coalescing element groups and enhanced sedimentation elements are added before and after the screen-type coalescing and separation internals.
This post was last edited by luoli519 on 2023-10-2 at 14:32. Adding a fin-separated pre-coalescing internal component in front of the coalescing screen serves the following purposes: 1. Streamlining effect. Prevent liquid-phase \"surges\" and distribute the flow velocity of the liquid stream across the radial cross-section of the separator housing ； 2. Pre-agglomeration effect. Some of the dispersed phase droplets in the fluid flow at the front end of the coalescing screen are removed in advance, thereby reducing the workload on the screen’s coalescing internals.